G'day itforsenior,
As a 1974 season model, that one was of the first model year to have the plastic G4 carby fitted.
These didn't have a primer bulb fitted ex-factory at all, so the one that's on it is a retrofit. The later versions on this chassis used a 'remote primer' setup, so that it could be used!
When a mower fitted with this carby suddenly loses spark, the crude cutout switch is always the first suspect.
